Hydraulic pumping system for expression of breast milk

ABSTRACT

A hydraulic pumping system in accordance with embodiments comprises a breast interface operably coupled to an actuatable assembly by means of an actuatable assembly interface. The breast interface comprises a distal membrane coupled to a housing to form a fluid reservoir therebetween. The actuatable assembly interface comprises a proximal membrane. The distal and proximal membranes are fluidly coupled via a tube carrying a driving fluid. The actuatable assembly interface is configured to removably couple to the actuatable assembly, in order to operably couple the actuatable assembly to the breast interface. The actuatable assembly interface comprises a fluid shut off mechanism to reversibly shut off fluid communication between the breast interface and the actuatable assembly interface when the actuatable assembly interface is decoupled from the actuatable assembly.

CROSS-REFERENCE

The present application is a non-provisional of, and claims the benefitof, U.S. Provisional Patent Application 62/329,917, filed on Apr. 29,2016 , the entire contents of which are incorporated herein byreference.

This application is related to the following co-pending provisional andnon-provisional patent applications: U.S. patent application Ser. No.14/221,113, filed on Mar. 20, 2014, now U.S. Pat. No. 9,616,156, U.S.patent application Ser. No. 14/616,557, filed on Feb. 6, 2015, U.S.patent application Ser. No. 14/793,606, filed on Jul. 7, 2015, U.S.patent application Ser. No. 14/793,613, filed on Jul. 7, 2015, U.S.patent application Ser. No. 14/793,617, filed on Jul. 7, 2015, U.S.patent application Ser. No. 14/858,924, filed on Sep. 18, 2015, now U.S.Pat. No. 9,623,160, U.S. patent application Ser. No. 15/094,690, filedon Apr. 8, 2016, U.S. patent application Ser. No. 15/094,704, filed onApr. 8, 2016, and U.S. patent application Ser. No. 15/349,917, filed onNov. 11, 2016, the entire contents of which are incorporated herein byreference.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention generally relates to medical and pediatricnutrition devices and methods, and more particularly relates to devicesand methods for expression and collection of human breast milk.

Breast pumps are commonly used to collect breast milk in order to allowmothers to continue breastfeeding while apart from their children. Manyexisting breast pumps are pneumatic systems, wherein a tube is attachedto a drive system to transmit vacuum from the drive system to a breastfluidly sealed against a breast interface. In hospital-grade pumpingsystems, a barrier is often placed between the breast interface and thedrive system to prevent cross-contamination between the drive system andthe breast interface. For example, the barrier can be a flexiblemembrane or a filter that can provide a barrier while facilitatingpressure transmission.

Hydraulic pumping systems for breast milk expression are described inco-pending U.S. patent application Ser. Nos. 14/221,113 and 14/793,613,the entire disclosures of which are incorporated herein by reference. Inthe described systems, the breast interface can comprise an expandablemembrane coupled to a rigid housing to form a fluid reservoirtherebetween, wherein movement of a driving fluid into or out of thereservoir via actuation of the actuatable assembly can causecorresponding contraction or expansion of the membrane. The expandablemembrane, when fluidly sealed against the breast, can transfer pressureto the breast, thereby causing the expression of milk from the breast.Hydraulic systems can reduce pumping force requirements, and thereforealso reduce the size of the pumping device, while maintaining highpumping efficiency.

As described in U.S. application Ser. No. 14/793,613, the breastinterface can be configured to removably couple to the actuatableassembly via an actuatable assembly interface, in order to preventcross-contamination between the breast interface and the actuatableassembly and facilitate the storage and maintenance of the device. Theactuatable assembly interface may comprise a flexible membraneconfigured to operably couple to the actuatable assembly, wherein theflexible membrane functions to both 1) transmit pressure between theactuatable assembly and the breast interface, and 2) provide a fluidbarrier to prevent cross-contamination between the actuatable assemblyand the breast interface. In contrast to air used to transfer pressurein pneumatic pumping systems, the driving fluid used in hydraulicsystems has a higher density than the atmosphere surrounding the drivingfluid. As a result, when either the breast interface or the actuatableassembly interface is positioned above the other, head pressure isapplied to the membrane of the component positioned below the other,causing the membrane to “bulge” outwards. In some cases, such bulging ofeither membrane can present challenges to the operation of the pumpingsystem. For example, the bulging of the membrane of the actuatableassembly interface can make it difficult for a user to couple theinterface to the actuatable assembly, or the bulging of the membrane ofthe breast interface can make it difficult for a user to fluidly sealthe breast interface against the breast.

Therefore, it would be desirable to provide hydraulic pumping systemsfor the expression of breast milk having improved means for removablycoupling the breast interface to the actuatable assembly. In particular,it would be desirable to provide means to fluidly decouple the breastinterface and the actuatable assembly interface when the actuatableassembly interface is disconnected from the actuatable assembly.

At least some of these objectives will be satisfied by the devices andmethods disclosed herein.

SUMMARY OF THE INVENTION

Hydraulic pumping systems for the expression of breast milk and methodsof use thereof are disclosed herein. A pumping system in accordance withembodiments comprises a breast interface operably coupled to anactuatable assembly by means of an actuatable assembly interface. Thebreast interface comprises an expandable membrane coupled to a housingto form a first fluid reservoir therebetween, wherein the first fluidreservoir is coupled to a distal end of a tube carrying a driving fluid.The proximal end of the tube is coupled to the housing of the actuatableassembly interface, wherein the housing is coupled to a proximalmembrane to form a second fluid reservoir therebetween. The first andsecond fluid reservoirs are in fluid communication via the tube, suchthat the driving fluid fills the space between the expandable membraneof the breast interface and the proximal membrane of the actuatableassembly interface. The actuatable assembly interface is configured toremovably couple to the actuatable assembly, in order to operably couplethe actuatable assembly to the proximal membrane. When the actuatableassembly interface is coupled to the actuatable assembly, actuation ofthe actuatable assembly causes movement of the proximal membrane movestowards and away from the breast interface, and thereby correspondingmovement of the driving fluid and hence the expandable membrane towardsand away from the breast, which applies negative pressure at the breastfluidly sealed against the breast interface to cause expression of milkfrom the breast.

The hydraulic pumping system may be configured to fluidly decouple thebreast interface and the actuatable assembly interface when theactuatable assembly interface is disconnected from the actuatableassembly. For example, the actuatable assembly interface may comprise amechanism to shut off fluid communication with the breast interface whenthe actuatable assembly interface is disconnected from the actuatableassembly, and re-open the fluid communication when the actuatableassembly interface is connected to the actuatable assembly. Such amechanism may be particularly advantageous for pumping systems utilizinga driving fluid that is substantially incompressible, such as water oroil, which has a higher density than the atmosphere surrounding thedriving fluid during typical use of the pumping system.

In one aspect, an apparatus for expression of breast milk from a breastcomprises a breast interface configured to receive and fluidly sealagainst the breast, the breast interface comprising a first fluidreservoir. The apparatus further comprises an actuatable assemblyinterface configured to removably couple to an actuatable assembly, theactuatable assembly interface comprising a second fluid reservoir. Theapparatus further comprises a tube having a first end coupled to thebreast interface and a second end coupled to the actuatable assemblyinterface, such that the first fluid reservoir and the second fluidreservoir are in fluid communication. The first fluid reservoir, thesecond fluid reservoir, and the tube are filled with a driving fluid,wherein the actuatable assembly interface comprises a fluid shutoffmechanism to reversibly shut off fluid communication between the firstfluid reservoir and the second fluid reservoir.

The driving fluid may have a density that is higher than the density ofair, or may substantially incompressible.

The breast interface may comprise a first housing and a distal membranecoupled thereto to form the first fluid reservoir therebetween. Theactuatable assembly interface may comprise a second housing and aproximal membrane coupled thereto to form the second fluid reservoirtherebetween. The distal and proximal membranes may be flexible to allowmovement of the driving fluid into or out of the first and second fluidreservoirs.

The proximal membrane may be configured to seal against an actuatableassembly membrane when the actuatable assembly interface is coupled tothe actuatable assembly. The actuatable assembly membrane may be coupledwith a driver mechanism of the actuatable assembly, such that movementof the actuatable assembly membrane in response to actuation of thedriver mechanism causes corresponding movement of the proximal membrane.The proximal membrane may comprise a sealing flap configured to allowair trapped between the proximal membrane and the actuatable assemblymembrane to exit.

The second housing of the actuatable assembly interface may comprise atube receiving member configured to couple to the second end of thetube, the tube receiving member defining a bore that is in fluidcommunication with the second fluid reservoir through an opening in thesecond housing. The tube receiving member may comprise a barbed regionconfigured to receive the tube thereover and form a fluid sealthereagainst. The actuatable assembly interface may further comprise abarbed adaptor configured to fit within and fluidly seal against thebore of the tube receiving member, the barbed adaptor comprising abarbed region configured to receive the tube thereover and form a fluidseal thereagainst.

The fluid shutoff mechanism may be configured to shut off fluidcommunication between the first and second fluid reservoirs in responseto detachment of the actuatable assembly interface from the actuatableassembly, and re-open the fluid communication in response to attachmentof the actuatable assembly interface to the actuatable assembly. Thefluid shutoff mechanism may be configured to simultaneously securecoupling of the actuatable assembly interface to the actuatable assemblyand release pinching of the tube to open the tube, and to simultaneouslyrelease coupling of the actuatable assembly interface to the actuatableassembly and pinch the tube closed.

The fluid shutoff mechanism may be configured to secure or release thecoupling of the actuatable assembly interface to the actuatable assemblyand simultaneously release or pinch the tube via rotational movement ofthe actuatable assembly interface with respect to the actuatableassembly.

The fluid shutoff mechanism may comprise one or more springs and one ormore engaging members configured to engage the one or more springs in afirst configuration when the actuatable assembly interface is detachedfrom the actuatable assembly, or in a second configuration differentfrom the first configuration when the actuatable assembly interface isattached to the actuatable assembly. The one or more springs maycomprise one or more material springs each having a detent geometry, thedetent geometry defining a first detent and a second detent configuredto engage the one or more engaging members in the first configuration orin the second configuration, respectively. The one or more springs maybe configured such that a greater force is required to disengage the oneor more engaging members from the one or more springs in the firstconfiguration than in the second configuration. The fluid shutoffmechanism may be configured to secure or release the coupling of theactuatable assembly interface to the actuatable assembly andsimultaneously release or pinch the tube via rotational movement of theactuatable assembly interface with respect to the actuatable assembly,and the one or more springs and one or more engaging members maycomprise a plurality of springs and a plurality of engaging membersdistributed rotationally about the actuatable assembly interface. Theplurality of springs and the plurality of engaging members may bedistributed in a rotationally symmetric manner about the actuatableassembly interface.

The actuatable assembly interface may comprise a keyed locking mechanismconfigured to allow attachment and removal of the actuatable assemblyinterface to and from the actuatable assembly only when the fluidcommunication between the first and second fluid reservoirs is shut off.

In another aspect, an apparatus for removably coupling a breastinterface with an actuatable assembly comprises a housing coupled to aproximal end of a tube, wherein a distal end of the tube is fluidlycoupled to a first fluid reservoir of the breast interface. Theapparatus further comprises a flexible membrane coupled to the housingto form a second fluid reservoir therebetween, the second fluidreservoir in fluid communication with the first fluid reservoir via thetube. The housing comprises a fluid shutoff mechanism to reversibly shutoff fluid communication between the first and second fluid reservoirs.

In another aspect, a system for expression of breast milk from a breastcomprises an actuatable assembly comprising a driver mechanism coupledto an actuatable assemble membrane, and an actuatable assembly interfaceconfigured to removably couple to the actuatable assembly. Theactuatable assembly interface comprises a housing and a flexiblemembrane coupled together to form a second fluid reservoir therebetween.The second fluid reservoir of the actuatable assembly interface is influid communication with a first fluid reservoir of a breast interfacevia a tube. The housing comprises a fluid shutoff mechanism toreversibly shut off fluid communication between the first and secondfluid reservoirs.

The flexible membrane may be configured to seal against the actuatableassembly membrane when the actuatable assembly interface is coupled tothe actuatable assembly, such that movement of the actuatable assemblymembrane in response to actuation of the driver mechanism causescorresponding movement of the flexible membrane. The flexible membranemay comprise a sealing flap configured to expel air trapped between theflexible membrane and the actuatable assembly membrane when the drivermechanism moves the actuatable assembly membrane towards the flexiblemembrane. The actuatable assembly may comprise a receiving surfaceconfigured to receive the actuatable assembly interface, the receivingsurface defining an sealing surface configured to seal against thesealing flap and an annular rib disposed about the outer periphery ofthe sealing surface. The annular rib may be vertically offset from thesealing surface by a height predetermined to allow sufficient movementof the sealing flap to expel the air trapped between the flexiblemembrane and the actuatable assembly membrane.

These and other embodiments are described in further detail in thefollowing description related to the appended drawing figures.

INCORPORATION BY REFERENCE

All publications, patents, and patent applications mentioned in thisspecification are herein incorporated by reference to the same extent asif each individual publication, patent, or patent application wasspecifically and individually indicated to be incorporated by reference.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of the invention are set forth with particularity inthe appended claims. A better understanding of the features andadvantages of the present invention will be obtained by reference to thefollowing detailed description that sets forth illustrative embodiments,in which the principles of the invention are utilized, and theaccompanying drawings of which:

FIG. 1 illustrates an exemplary embodiment of a breast milk expressionapparatus or pumping device in accordance with embodiments.

FIG. 2 illustrates an exemplary embodiment of a hydraulic pumpingsystem.

FIG. 3A is a cross-section of an exemplary embodiment of a hydraulicpumping system comprising an actuatable assembly interface.

FIG. 3B is a cross-section of an actuatable assembly coupled to theactuatable assembly interface of FIG. 3A.

FIG. 4A illustrates an exemplary embodiment of a hydraulic pumpingsystem, wherein the breast interface and the actuatable assemblyinterface are positioned at an equal height.

FIG. 4B illustrates the exemplary embodiment of the hydraulic pumpingsystem of FIG. 4A, wherein the breast interface is positioned above theactuatable assembly interface.

FIG. 4C illustrates the exemplary embodiment of the hydraulic pumpingsystem of FIG. 4A, wherein the breast interface is positioned above theactuatable assembly interface, while fluid communication between thebreast interface and the actuatable assembly interface is shut off.

FIG. 5 is an exploded view of an exemplary embodiment of an actuatableassembly interface coupled to an actuatable assembly.

FIG. 6A is an isometric view of the locking ring assembly of theactuatable assembly interface of FIG. 5.

FIG. 6B is a top view of the locking ring assembly of the actuatableassembly interface of FIG. 5.

FIG. 7A shows the cover, base, and tube of the actuatable assemblyinterface of FIG. 5 assembled together.

FIG. 7B is a side cross-sectional view of the partial assembly of theactuatable assembly interface shown in FIG. 7A.

FIGS. 8A-8C show the actuatable assembly interface of FIG. 5 coupled toa locking portion of the actuatable assembly, in the unlockedconfiguration.

FIGS. 9A-9C show the actuatable assembly interface of FIG. 5 coupled toa locking portion of the actuatable assembly, in the lockedconfiguration.

FIGS. 10A-10B illustrate the locking of the actuatable assemblyinterface of FIG. 5 onto a locking portion of an actuatable assembly.

FIG. 11 is a cross-sectional view of a flexible actuatable assemblyinterface membrane suitable for incorporation with a hydraulic pumpingsystem as disclosed herein.

FIG. 12A shows an exemplary configuration of an actuatable assembly inaccordance with embodiments.

FIG. 12B is a side cross-sectional view of an actuatable assembly inaccordance with embodiments.

FIG. 13 is a side cross-sectional view of the actuatable assembly ofFIGS. 12A and 12B coupled to an actuatable assembly interface inaccordance with embodiments.

FIG. 14A shows an exemplary configuration of a locking ring of anactuatable assembly interface in accordance with embodiments.

FIG. 14B shows an exemplary configuration of an actuatable assemblyinterface base in accordance with embodiments.

FIG. 14C is a top view of an exemplary actuatable assembly interface inthe unlocked configuration.

FIG. 14D is a top view of the actuatable assembly interface of FIG. 14Cin the locked configuration.

FIG. 15A shows a barbed adaptor suitable for incorporation with anactuatable assembly interface as described herein.

FIG. 15B shows the barbed adaptor of FIG. 15A coupled to an actuatableassembly interface in accordance with embodiments.

FIG. 15C is a side cross-sectional view of the actuatable assemblyinterface of FIG. 15B.

DETAILED DESCRIPTION OF THE INVENTION

Specific embodiments of the disclosed devices and methods will now bedescribed with reference to the drawings. Nothing in this detaileddescription is intended to imply that any particular component, feature,or step is essential to the invention.

The exemplary embodiments disclosed herein are preferably directed atexpression of breast milk, but one of skill in the art will appreciatethat this is not intended to be limiting and that the devices, systemsand methods disclosed herein may be used for other treatments requiringapplication of a differential pressure.

FIG. 1 illustrates an exemplary embodiment of a breast milk expressionapparatus or pumping device in accordance with embodiments. Pumpingdevice 100 (also known as an “expression apparatus”) includes breastinterfaces 105, a tube 110, and a controller 115 operatively coupled tobreast interfaces 105 through tube 110. Breast interfaces 105 includeresilient and conformable flanges 120, for engaging and creating a fluidseal against the breasts. Each breast interface 105 is fluidly coupledto a collection vessel 125 configured to receive the expressed breastmilk. Each breast interface 105 is additionally coupled to one or morecontrollers 115 that house the power source and drive mechanism for thepumping device 100. For example, the controller 115 may comprise anactuatable assembly for generating negative and/or positive pressure atthe breast interface to cause expression of milk from a breast fluidlysealed against the breast interface. Tube 110 may transmit suitableenergy inputs, such as mechanical energy generated by an actuatableassembly housed within the controller, from controller 115 to breastinterfaces 105. Breast interfaces 105 can then convert the energy inputsinto pressure applied against the breasts in a highly efficient manner,resulting in the expression of milk into collection vessels 125. Forexample, as described in further detail herein, the breast interface maycomprise an expandable membrane coupled to a rigid housing, wherein theexpandable member expands and contracts in response to actuation of theactuatable assembly apply pressure at the breast and thereby causeexpression of milk from the breast.

The controller 115 may further comprise hardware for various functions,such as controlling the pumping device 100, quantifying milk expression,measuring or analyzing data related to characteristics of the expressedmilk, and/or communicating with other devices. For example, thecontroller may be configured to communicate with one or more personalcomputing devices such as smartphones, tablets, or personal computers,wherein the personal computing device may be configured to provide auser interface for a user to interact with the pumping device.

The device 100 may further comprise one or more sensors configured totrack various characteristics of the collected fluid, such as thequantity of the fluid or a composition of the fluid. The one or moresensors may be coupled to one or more portions of the breast interfacesor the collection vessels, or they may be coupled to controller. Powermay be provided to the one or more sensors via a connection to thecontroller 115, or to another source of power. In embodiments in whichthe one or more sensors are coupled to one or more portions of thebreast interfaces 105 or collection vessels 125, the sensors may befurther coupled to the controller 115 via one or more communicationlines configured to transmit signals between the sensors and thecontroller.

One of skill in the art will appreciate that components and features ofthis exemplary embodiment can be combined or substituted with componentsand features of any of the embodiments of the present invention asdescribed below. Similarly, components and features of other embodimentsdisclosed herein may be substituted or combined with one another.

FIG. 2 illustrates an exemplary embodiment of a hydraulic pumping system200. The hydraulic pumping system comprises a breast interface 205 andan actuatable assembly 215, operably coupled together by a tube 225carrying a driving fluid 230.

The breast interface 205 comprises an interface housing 240 and anexpandable membrane 245 coupled together to form a reservoir 250therebetween. The housing 240 can be coupled to a distal end of the tube225, such that the reservoir 250 is in fluid communication with the tubeand can be filled with the driving fluid 230. The expandable membrane245 comprises a flange or sealing portion 255 configured to fluidly sealagainst a breast received within the breast interface, and an expandableor deformable portion 270 configured to expand and contract in responseto the removal and addition of driving fluid 230 from/to the reservoir250. The sealing portion 255 may comprise a thickness greater than thethickness of the deformable portion 270, as shown. The expandablemembrane may have a distal opening 260 through which the nipple and/orsurrounding breast tissue is received, and proximal opening or drainport 265 through which expressed breast milk may exit the breastinterface and enter a collection vessel 275 coupled to the breastinterface. An expression area 280 may be defined between the distalopening and the proximal opening, wherein the milk is expressed from thebreast into the expression area, then subsequently collected into thecollection vessel through the drain port. Optionally, a one-way valvesuch as a flap, duckbill, or ball valve may be disposed over the drainport 265 to provide passage of milk into the collection vessel 275 whilemaintaining vacuum pressure in expression area 280.

The actuatable assembly 215 may comprise an assembly housing 210, adriving element 235, radial seals 220, and a shaft 222. Driving element225 may be operatively coupled to a controller, such as controller 115of FIG. 1, through shaft 222.

In operation, actuation of the actuatable assembly 215 displaces thedriving fluid 230 contained within tube 225, which can be a flexibleline. Fluid 230 occupies reservoir 250 within breast interface 205 andis coupled with expandable membrane 245. The deformable portion 270 ofthe expandable membrane 245 can be configured to expand or move towardsthe housing 240 in response to the displacement of the driving fluid outof the reservoir, and contract or move away from the housing in responseto displacement of the driving fluid into the reservoir. When theexpandable membrane expands, the membrane moves away from the breastreceived within the breast interface, thereby creating negative pressureat the breast. When the expandable membrane contracts, the membranemoves towards the breast, thereby increasing the pressure at the breastto return the pressure to a baseline level prior to the expansion of theexpandable membrane. Thus, when a breast is engaged into and fluidlysealed against the sealing element 255 of the expandable membrane,displacement of the driving element 235 in the proximal direction awayfrom the breast can produce substantial vacuum pressure against thebreast through the deformable portion of the expandable membrane,resulting in the expression of breast milk into the expression area 280.The expressed milk drains through drain port 265 into collection vessel275.

The reservoir 250 can therefore provide a sole source of negativepressure for the breast interface, wherein movement of the fluid 230 inor out of the reservoir and corresponding movement of the membrane 245towards or away from the breast can generate sufficient negativepressure against the breast to cause the expression of milk, without theaid of additional pressure sources such as air suction applied directlyto the nipple. The driving fluid may comprise any suitable fluid fortransferring sufficient pressure from the actuatable assembly to theexpandable membrane to cause expression of milk from the breast. In manyembodiments, the driving fluid may be as a substantially incompressiblefluid, such as water or oil. Suitable incompressible fluids forhydraulic systems are known to those of skill in the art.

The expandable membrane 245 may comprise a flexible or elastic materialallowing the membrane to elastically deform in response to the actuationof the pumping mechanism. For example, the expandable membrane maycomprise one or more of silicone, polyether block amides such as PEBAX,or polychloroprenes such as neoprene, and can have a specified thicknessand durometer. Alternatively or additionally, the expandable membrane245 may comprise a membrane having one or more corrugated features (suchas pleats) that allow expansion and contraction of the membrane. Theexpandable membrane having the one or more corrugated features maycomprise an elastically deformable material or a substantially rigidmaterial, such as stainless steel, nitinol, high durometer polymer, orhigh durometer elastomer. The one or more corrugated features canprovide stress and/or strain distribution to enable the substantialdeformation of the expandable membrane without surpassing the yieldpoint of the material. The amount of deformation of the expandablemembrane can be controlled by many factors, (e.g., wall thickness,durometer, surface area) and can be optimized based on the pumpingdevice (e.g., pump power, vacuum requirements).

One of skill in the art will appreciate that components and features ofany of the exemplary embodiments of the hydraulic pumping system can becombined or substituted with components and features of any of theembodiments of the present invention as described herein.

An actuatable assembly for a breast milk expression device as describedherein can be configured to removably couple to the breast interfaceassembly, so as to keep the driving fluid carried in the transmissionlines (such as the tube described herein) and in the breast interfacephysically separate from the actuatable assembly. Such a physicalseparation between the actuatable assembly and the fluid in the breastinterface can help prevent cross-contamination between the breastinterface and the actuatable assembly. Further, the easy separation ofvarious components of the expression device can facilitate the storageand maintenance of the device.

FIG. 3A is a cross-section of an exemplary embodiment of a hydraulicpumping system 300 comprising an actuatable assembly interface 385. Theactuatable assembly interface (AAI) 385 can removably couple to theactuatable assembly 315, so as to operatively couple the actuatableassembly to the breast interface 305, while keeping the mechanisms ofthe actuatable assembly separate from the fluid 330 in the tubing 325and in the fluid reservoir 350 of the breast interface 305. The AAI 385may comprise a flexible membrane 389 coupled to a housing 387 to form afluid reservoir 386 therebetween. The AAI fluid reservoir 386 may be influid communication with the breast interface fluid reservoir 350 viathe tube 325, such that the fluid 330 can move into and out of thereservoir 386. When the AAI 385 is coupled to the actuatable assembly315, the actuation of the actuatable assembly can cause movement of theAAI membrane 389, in turn causing the fluid 330 to be pulled into orpushed out of the AAI fluid reservoir 386. This, in turn, causes thefluid 330 to be pulled out of or pushed into the fluid reservoir 350 ofthe breast interface, thereby causing an expandable membrane 345 of thebreast interface to apply pressure to the breast engaged into the breastinterface. Thus, the flexible AAI membrane 389 can function to bothtransmit pressure between the actuatable assembly and the breastinterface, and provide a fluid barrier to prevent cross-contaminationbetween the actuatable assembly and the breast interface. The breastinterface 305, AAI 385, and tubing 325 can collectively form the breastshield assembly 301, an enclosed, fluidly sealed assembly that caneasily attach to and detach from an actuatable assembly to transferpressure from the actuatable assembly to a breast.

FIG. 3B is a cross-section of an actuatable assembly 315 coupled to anactuatable assembly interface 385, as illustrated in FIG. 3A. Theactuatable assembly interface (AAI) 385 comprises an actuatable assemblyinterface house (AAI housing) 387 and a flexible actuatable assemblyinterface membrane (AAI membrane) 389 coupled thereto to form a fluidreservoir 386 therebetween. The AAI housing is configured to couple totubing 325, which is fluidly coupled to the fluid reservoir of thebreast interface. The tubing 325 is operatively coupled to the AAImembrane 389, such that movement of the AAI membrane causes movement ofthe driving fluid 330 carried by the tubing. The actuatable assembly 315comprises an actuatable assembly housing (AA housing) 310 and anactuatable assembly membrane (AA membrane) 312 coupled thereto. The AAmembrane is operatively coupled to the driver mechanism 335 of theactuatable assembly, such that actuation of the driver mechanism causesmovement of the membrane 312. The driver mechanism may comprise any pumpmechanism as described herein or as known in the art. For example, thedriver mechanism may comprise a piston assembly shown in FIG. 3B, thepiston configured to move in response to movement of the lead screw 322driven by a motor.

The AA housing 310 may be configured to removably couple to the AAIhousing 385, for example via one or more magnets 391 as shown. Themagnets may be embedded in the AAI housing, the AA housing, or both;accordingly, one or more of the AAI housing and the AA housing maycomprise a metal material configured to be attracted to the magnets. Theactuatable assembly may further comprise an alignment mechanism 324,such as pins or screws configured to engage a portion of the AAI, inorder to ensure correct alignment of the actuatable assembly with theAAI.

When the actuatable assembly and the AAI are coupled together, the AAmembrane 312 and the AAI membrane 389 are brought into communicationwith one another. As the motor of the actuatable assembly is actuated,the driver mechanism 335 pushes the membrane 312 upward toward the AAImembrane 389, causing at least a portion of the air trapped between thetwo membranes to be pushed out via a one-way valve 393 coupled to eitherthe actuatable assembly or the AAI. In order to ensure that the AAI doesnot separate from the actuatable assembly during coupling of the twomembers, the magnets 391 may be configured to have a magnetic force thatis greater than the exit force of air from the one-way valve. Once thetrapped air is pushed out through the valve outlet 395, the AAI membrane389 becomes operatively coupled to the AA membrane 312, such the AAImembrane will follow the cyclical motions of the AA membrane as theactuatable assembly is actuated. Movement of the AAI membrane 389 willcause corresponding movement of the driving fluid 330 in the tubing 325,causing fluid to be removed from or added to the fluid reservoir in thebreast interface.

FIG. 4A illustrates an exemplary embodiment of a hydraulic pumpingsystem 400 comprising a breast shield assembly 401, wherein the breastinterface 405 and the actuatable assembly interface (AAI) 485 arepositioned at an equal height. As described herein, the breast interfacecomprises an expandable membrane 445, also referred to herein as thedistal membrane of the pumping system, and the AAI comprises a flexiblemembrane 489, also referred to herein as the proximal membrane of thepumping system. The distal and proximal membranes are operably coupledtogether with the driving fluid 430, which is transferred between thefirst fluid reservoir 450 of the breast interface and the second fluidreservoir 486 of the AAI via the tubing 425. When the breast interfaceand the AAI are positioned at an equal height, no significant headpressure is applied to either the distal membrane or the proximalmembrane, and the membranes take their default resting positions asshown in FIG. 4A. In particular, the proximal membrane 489 sits flushagainst the inner surface of the AAI housing 487, with minimal fluidvolume present inside the fluid reservoir 486, such that the AAI caneasily be placed over and coupled to the actuatable assembly.

FIG. 4B illustrates the exemplary embodiment of the hydraulic pumpingsystem 400 of FIG. 4A, wherein the breast interface 405 is positionedabove the AAI 485. In contrast to air used to transfer pressure inpneumatic pumping systems, the driving fluid 430 used in the hydraulicpumping system has a higher density than the atmosphere surrounding thedriving fluid. As a result, when either the breast interface or theactuatable assembly interface is positioned above the other, headpressure is applied to the membrane of the component positioned belowthe other, causing the membrane to distend or “bulge” outwards. Forexample, as shown in FIG. 4B, when the breast interface is positionedabove the AAI, head pressure 490 is applied to the proximal membrane489, causing distension of the proximal membrane in the downwarddirection. Such bulging of the proximal membrane can make it difficultfor a user to couple the interface to the actuatable assembly, as thedriving fluid needs to be pushed out of the AAI in order to be able toalign and couple the AAI with the actuatable assembly. In addition, themovement of the driving fluid from the breast interface to the AAIcauses a corresponding reduction in volume of the fluid reservoir 450 ofthe breast interface, formed between the breast interface housing 440and the distal membrane 445, and expansion of the distal membrane asshown. Fluidly sealing a breast against the breast interface while thedistal membrane is expanded as such, and subsequently actuating theactuatable assembly to begin pumping, may result in inefficientexpression of milk, since the distal membrane is already in an expandedconfiguration and may not be able to expand substantially further toeffectively create negative pressure at the breast.

FIG. 4C illustrates the exemplary embodiment of the hydraulic pumpingsystem 400 of FIG. 4A, wherein the breast interface 405 is positionedabove the AAI 485, while fluid communication between the breastinterface and the AAI is shut off. Shutting off fluid communicationbetween the breast interface and the AAI, such as in manner 492 asshown, effectively decouples the distal membrane 445 from the proximalmembrane 489. In this configuration, even when the breast interface ispositioned above the AAI, the driving fluid 430 is unable to move fromthe fluid reservoir 450 at the breast interface into the fluid reservoir486 at the AAI to push against the proximal membrane 489. Thus, shuttingoff fluid communication between the breast interface and the AAI whilethe pumping system is inactive can help ensure that: 1) the distalbreast interface membrane is in the proper configuration for beginningpumping; and 2) the proximal AAI membrane is in the proper configurationfor coupling the AAI to the actuatable assembly.

The AAI may be configured in one of many ways to shut off fluidcommunication between the breast interface and the AAI when the AAI isdisconnected from the actuatable assembly, then re-establish the fluidcommunication once the AAI is connected to the actuatable assembly.Preferably, the AAI and/or the actuatable assembly comprise a mechanismto automatically shut-off or re-establish fluid communication betweenthe breast interface and the AAI in response to the decoupling andcoupling, respectively, of the AAI to the actuatable assembly, withoutrequiring separate action from a user to toggle the fluid communicationon and off

FIG. 5 is an exploded view of an exemplary embodiment of an actuatableassembly interface (AAI) 500 coupled to an actuatable assembly 600. TheAAI 500 comprises a housing 502 and a flexible AAI membrane 504, alsoreferred to herein as proximal membrane. The housing 502 comprises oneor more components collectively configured to provide a lockingmechanism for locking onto a corresponding locking portion 605 of theactuatable assembly 600. In the embodiment shown in FIG. 5, the housing502 comprises a cover 506, an internal locking ring 508, an externallocking ring 510, and a base 512. The AAI membrane 504 can be coupled tothe bottom of the base 512. Tube 514, carrying the driving fluid for thepumping system and fluidly coupling the AAI to a breast interface, canalso be coupled to the AAI via the base 512. The cover can be keyed andcoupled to the base. The internal locking ring and external locking ringtogether form the locking ring assembly 516, which can rotate withrespect to the base and the cover to provide a fluid communicationshut-off mechanism, as described in further detail herein. The lockingring assembly can also rotate with respect to the locking portion 605 tolock the AAI onto the actuatable assembly. The AAI may be rotationallysymmetric in shape to provide a rotational locking mechanism forcoupling onto the actuatable assembly, wherein the AAI can be coupled toor decoupled from the actuatable assembly via rotational movement of theAAI with respect to the actuatable assembly. For example, as shown,components of the AAI such as the base, cover, locking ring assembly,and AAI membrane may have a generally circular footprint, and thelocking portion of the actuatable assembly may have a correspondingshape to receive the AAI.

FIG. 6A is an isometric view and FIG. 6B is a top view of the lockingring assembly 516 comprising the internal locking ring 508 and externallocking ring 510 of the AAI 500. The internal locking ring and externalrocking ring may be coupled together so as to rotate together. Forexample, the external locking ring 510 may comprise one or more torquetransmission members 518, such as protrusions extending radially inwardstowards the internal locking ring. The torque transmission members maytransmit torque to the internal locking ring by pushing onto theinternal locking ring, or the internal locking ring may comprise one ormore grooves, indents, holes, or other mechanisms for receiving thetorque transmission members. Optionally, the internal and externallocking rings may be formed as a single component, rather than asseparate components that are coupled together.

The external locking ring may comprise one or more handling portions 520to facilitate manipulation of the locking ring assembly by a user. Forexample, as shown, the handling portions may comprise one or moreregions protruding upwards. Alternatively or additionally, the handlingportions may comprise handles, knobs, radial protrusions, indentedregions, textured outer surfaces, or any other suitable means offacilitating the grabbing and rotating of the locking ring assembly by auser.

The internal locking ring may comprise a partial ring having two ends,wherein a first end may comprise a fluid communication shutoff mechanismsuch as a material spring 522. The material spring may comprise a detentgeometry, which may be built into the material spring as shown.Alternatively, the spring may comprise separate components that functionas detents, such as ball plungers or leaf fingers. The detent geometrycan comprise an open detent 524 and a shutoff detent 526, wherein theopen detent and the shutoff detent are configured to alternatingly holda corresponding engaging element of the base. When AAI is not lockedonto the actuatable assembly, the engaging element is held in theshutoff detent, and fluid communication between the breast interface andthe AAI is shut off. When the AAI is fully locked onto the actuatableassembly, the engaging element is held in the open detent, and fluidcommunication between the breast interface and the AAI is re-opened. Thesecond end of the internal locking ring may comprise a tip 528configured to push against the tube carrying the driving fluid, therebypinching the tube shut, when an engaging element is held in the shutoffdetent 526. As shown in FIGS. 6A and 6B, the open detent 524 and theshutoff detent 526 may have slightly different sizes or shapes, suchthat a different amount of force is required for an engaging element tomove from the open detent to the shutoff detent than to move from theshutoff detent to the open detent. Preferably, the detent geometry isconfigured to require greater force for an engaging element to move fromthe shutoff detent to the open detent, than from the open detent to theshutoff detent. For example, the open detent can comprise a shallowerindentation than the shutoff detent, or the two detents may comprisematerials with varying stiffness or other material properties. Such aconfiguration can prevent accidental movement of the engaging elementfrom the shutoff detent to the open detent, to help ensure that whilethe AAI is not locked onto the actuatable assembly (e.g., during storageof the pumping system), the fluid communication between the breastinterface and the AAI remains securely shut off.

FIG. 7A shows the cover 506, base 512, and tube 514 of the actuatableassembly interface (AAI) 500 assembled together. As described herein,the tube 514 carrying the driving fluid for the hydraulic pumping systemis coupled to the base 512. The cover 506 may comprise a rounded notch532 disposed along the bottom edge of the rounded side wall, configuredto be positioned over the tube 514 when the cover is coupled to thebase, such that the tube 514 coupled to the base is allowed to protrudefrom the base-cover assembly without being pinched or deformed by thecover. The cover may further comprise one or more rectangular notches534 disposed along the bottom edge of the side wall. The one or morerectangular notches can form windows 536 when the cover is coupled tothe base. In the complete AAI assembly, the internal locking ring 508 isdisposed within the base-cover assembly shown in FIG. 7A, while theexternal locking ring 510 is disposed about the periphery of thebase-cover assembly. The one or more windows 536 can function to allowthe torque transmitting members 518 of the external locking ring 510, asshown in FIGS. 6A and 6B, to pass from the external locking ring to theinside of the base-cover assembly to connect with the internal rotatingring 508. The number and positions of the rectangular notches 534, andhence windows 536, may be configured to match the number and positionsof torque transmitting members. To lock the AAI onto the actuatableassembly or unlock the AAI from the actuatable assembly, the externallocking ring is rotated about the base-cover assembly while the base isengaged with the locking portion of the actuatable assembly. The sidewalls of the base and the cover provide bearing surfaces 538 for theexternal locking ring during the rotation of the external locking ring.The windows 536 may extend over a sufficient length to allow rotation ofthe torque transmitting members within the windows while the AAI islocked onto or unlocked from the actuatable assembly.

FIG. 7B is a side cross-sectional view of the partial assembly of AAI500 shown in FIG. 7A. The base 512 comprises a tube receiving member 530configured to couple to the tube 514. The tube receiving member 530 maydefine a bore 531 sized and shaped to receive the tube 514 therein,wherein the bore is in fluid communication with the fluid reservoir 586of the AAI 500, formed between the AAI membrane 504 and the base 512,through an opening 513 formed through the bottom of the base.

FIGS. 8A-8C show the actuatable assembly interface (AAI) 500 coupled tothe locking portion 605 of the actuatable assembly, in the unlockedconfiguration. FIG. 8A shows an isometric view of the assembly, FIG. 8Bshows a top view of the assembly, and FIG. 8C shows a close-up view of aportion of the top view of FIG. 8B. As best seen in FIG. 8B, the tube514 carrying the driving fluid couples to the base 512, for example viaa tube receiving member 530 coupled to or integrally formed with thebase. As best seen in FIG. 8A, the external locking ring 510 comprises acut-out 540 along its side wall, configured to allow passage of the tube514 therethrough. The cut-out may extend over a sufficient length toallow rotation of the tube within the cut-out while the AAI is lockedonto or unlocked from the actuatable assembly. In the unlockedconfiguration, the tube is disposed adjacent a first end 546 of thecut-out. As best seen in FIG. 8C, the base 512 comprises an engagingelement 542, configured to engage either the open detent 524 or theshutoff detent 526 of spring 522 of the internal locking ring 508. Whenthe AAI is not locked onto the actuatable assembly, fluid communicationbetween the breast interface and the AAI is preferably shut off, inorder to prevent distension of either the breast interface membrane orthe AAI membrane as described herein. Thus, in the unlockedconfiguration of FIGS. 8A-8C, the engaging element 542 is held in theshutoff detent 526, and correspondingly, the end 528 of the internallocking ring 508 pinches the tube 514 to shut off the fluidcommunication. The engaging element may be supported by one or moresupporting elements 544 to help prevent bending or breakage of theengaging element in response to the forces applied to the engagingelement by the spring 522 as the locking ring assembly is rotated withrespect to the base.

FIGS. 9A-9C show the actuatable assembly interface (AAI) 500 coupled tothe locking portion 605 of the actuatable assembly, in the lockedconfiguration. FIG. 9A shows an isometric view of the assembly, FIG. 9Bshows a top view of the assembly, and FIG. 9C shows a close-up view of aportion of the top view of FIG. 9B. As best seen in FIG. 9A, in thelocked configuration, the tube 514 passing through the cut-out 540 ofthe external locking ring 510 is disposed adjacent a second end 548 ofthe cut-out opposite the first end 546 as shown in FIG. 8A. When the AAIis locked onto the actuatable assembly, fluid communication between thebreast interface and the AAI can be re-opened, in order to allow thetransfer of pressure from the actuatable assembly to the breastinterface. Thus, in the locked configuration of FIGS. 9A-9C, theengaging element 542 of the base 512 is held in the open detent 524, andcorrespondingly, the end 528 of the internal locking ring 508 isdecoupled from the tube 514, to allow fluid communication to resumebetween the AAI and the breast interface.

FIGS. 10A-10B illustrate the locking of the actuatable assemblyinterface (AAI) 500 onto a locking portion 605 of an actuatableassembly. As described herein, the AAI 500 comprises a locking ringassembly rotatably coupled to a base-cover assembly, wherein the lockingring assembly comprises an external locking ring 510 configured torotate over the external bearing surface of the base 512. The externallocking ring is rotationally coupled with the internal locking ringdisposed within the base-cover-assembly, such that rotation of theexternal locking ring with respect to the base can re-open or shut offfluid communication between the AAI and the breast interface, asdescribed herein. The locking portion 605 of the actuatable assemblycomprises a protruding side wall 610 configured to fit within the space554 between the external locking ring 510 and the base 512. To operablyconnect the AAI to the actuatable assembly, the AAI can be placed overthe locking portion 605 with the space 554 aligned with the side wall610 of the locking portion. The AAI can then be rotated into a lockedposition, such that the flexible AAI membrane 504, coupled to the bottomof the base 512, becomes fluidly sealed against the AAI receivingsurface 615 of the locking portion 605, and the AAI is securely lockedonto the actuatable assembly. The locking of the AAI onto the actuatableassembly can simultaneously re-open fluid communication between thebreast interface and the AAI, as described herein.

To facilitate proper rotational alignment of the AAI with respect to thelocking portion, each of the external locking ring 510 and base 512 maycomprise mechanisms to align and/or lock the AAI onto the lockingportion of the actuatable assembly. The base 512 may comprise one ormore base aligning features 556, such as one or more rib slots disposedon an external surface of the base side wall and extending through thebottom edge of the side wall. The protruding side wall 610 of thelocking portion 605 may comprise one or more base aligning members 620configured to couple to the base aligning features 556, such as one ormore ribs disposed on an internal surface of the side wall 610configured to fit within the one or more rib slots of the base. Theexternal locking ring 510 may comprise one or more key members 550, suchas one or more cam pins disposed on an internal surface of the lockingring side wall, protruding radially inwards. The side wall 610 of thelocking portion 605 may comprise one or more lock members 625corresponding to the one or more key members 550. For example, the oneor more lock members may comprise one or more cam paths configured toreceive one or more cam pins of the external locking ring therein. Thecam paths may be slots or grooves disposed along the external surface ofthe protruding side wall 610, wherein a cam path may comprise an entryregion 626, a ramped region 627, and a locking region 628. The entryregion 626 can extend through the top edge of the side wall to providean entry path for the cam pin of the external locking ring as the AAI isinitially lowered into the coupling portion. The ramped region 627 canprovide a translational path for the cam pin that slopes slightlydownwards. The locking region 628 can lock the AAI into position suchthat the AAI can resist the vertical thrusting force during actuation ofthe actuatable assembly.

To couple the AAI 500 to an actuatable assembly as shown in FIGS.10A-10B, one or more cam pins 550 of the external locking ring 510 canbe aligned with the entry regions 626 of one or more corresponding campaths 625 of the locking portion 605, while one or more rib slots 556 ofthe base 512 can be aligned with one or more corresponding ribs 620 ofthe locking portion. Next, the external locking ring may be rotated inthe direction 650, such that the cam pin rotatingly translates withinthe ramped region 627 of the cam path towards the locking region 628. Asthe AAI is rotated, translation of the cam pin along thedownward-sloping ramped region brings the flexible AAI membrane 504closer to the AAI receiving surface 615 of the coupling portion 605.Eventually, the AAI membrane 504 is compressed against the AAI receivingsurface such that the membrane becomes fluidly sealed against the AAIreceiving surface. The AAI is rotated until the cam pin reaches andbecomes securely held within the locking region of the cam path.

When the AAI is initially lowered onto the locking portion of theactuatable assembly, with the cam pin aligned with the entry region ofthe cam path, the engaging element 542 of the base 512 is held withinthe shutoff detent 526 of the internal locking ring 508, as shown inFIG. 8C. In this configuration, the end 528 of the internal locking ringis compressed against the tube 514 carrying the driving fluid, such thatfluid communication between the breast interface and the AAI is shutoff. As the external locking ring is rotated against the actuatableassembly to translate the cam pin from the entry region to the lockingregion, sufficient rotational force is exerted to overcome theresistance of the material spring 522 as the engaging element is heldwithin the shutoff detent, and the internal locking ring rotates suchthat open detent 524 engages the engaging element, as shown in FIG. 9C.Thus, as the AAI is operably coupled with and securely locked onto theactuatable assembly, the fluid communication between the AAI and thebreast interface is simultaneously re-opened.

To unlock the AAI from the actuatable assembly, the AAI can be rotatedin a direction opposite the direction 650 as shown in FIG. 10B, suchthat the cam translates along the cam path from the locking region tothe entry region, and the AAI membrane is decoupled from the AAIreceiving surface of the locking portion. This rotational unlockingmovement simultaneously causes the internal locking ring to rotate withsufficient force to deflect the material spring and cause the shutoffdetent to re-engage the engaging element. Engagement of the engagingelement in the shutoff detent causes the internal locking ring end tofully compress against and pinch off the tube carrying the drivingfluid, thereby shutting off the fluid communication between the breastinterface and the AAI. The AAI can then be removed from the actuatableassembly by lifting the AAI upwards, with the cam pin translating alongthe entry region of the cam path.

FIG. 11 is a cross-sectional view of a flexible AAI membrane 504suitable for incorporation with a hydraulic pumping system as disclosedherein. The AAI membrane 504 may comprise an annular lip 560 configuredto engage a corresponding annular groove formed in the base, to securelycouple to the AAI membrane to the base. The AAI membrane may furthercomprise a sealing flap or flange 558 disposed at its proximal endfacing the actuatable assembly, and extending annularly about theperiphery of the membrane. The sealing flap may extend proximally beyondthe bottom surface of the base, such that the sealing flap engages theAAI receiving surface of the locking portion of the actuatable assemblywhen the AAI is coupled to the locking portion of the actuatableassembly. The sealing flap may be configured to deform on contact toallow at least a portion of the air trapped between the AAI membrane theAAI receiving surface to escape, but not easily re-enter. The sealingflap can thus facilitate the formation of a fluid seal between the AAIand the actuatable assembly. Various design parameters of the sealingflap may be modified such that the sealing flap can form a completefluid seal against the actuatable assembly when the actuatable assemblyis actuated. For example, the thickness and/or geometry of the flap maybe modified, or the height at which the sealing flap is seated againstthe AAI receiving surface when the AAI is locked onto the actuatableassembly may be modified, such that the sealing flap can allowsubstantially all of the air trapped between the AAI and the actuatableassembly to escape the space when the actuatable assembly is actuated. Athus-configured sealing flap may eliminate the need for a separateone-way valve coupled to either the actuatable assembly or the AAI toallow air trapped between the two parts to be pushed out, such as theone-way valve 393 shown and described with reference to FIG. 3B.

FIGS. 12A-12B illustrate an exemplary configuration of an actuatableassembly suitable for incorporation with a hydraulic pumping system asdisclosed herein. FIG. 12A is an isometric view of a locking portion 705of actuatable assembly 700. FIG. 12B is a side cross-sectional view of aportion of actuatable assembly 700 including the locking portion 705.Actuatable assembly 700 may comprise a locking portion 705 configured tocouple to an actuatable assembly interface of a breast shield assemblyas described herein. Locking portion 705 may be similar in many aspectsto locking portion 605 as shown in and described in reference to FIGS.5-10B. For example, the locking portion 705 may comprise an AAIreceiving surface 715, one or more base aligning members 720, and/or oneor more lock members 725 such as one or more cam paths formed in theside wall 710.

AAI receiving surface 715 may comprise a sealing surface 735 configuredto seal against the sealing flap or flange of the AAI membrane asdescribed herein. The AAI receiving surface may further comprise anannular rib 730, which may be disposed about the outer periphery of thesealing surface 735. The annular rib 730 may be a single, continuousrib, or it may comprise a plurality of portions arranged annularly, asbest shown in FIG. 12A. The annular rib may have a vertical offset 740with respect to the sealing surface 735, as best shown in FIG. 12B. Thevertical offset may be calibrated to allow movement of the sealing flapof the AAI membrane when the AAI is coupled to the actuatable assembly,as described in further detail with reference to FIG. 13.

FIG. 13 is a side cross-sectional view of the actuatable assembly ofFIGS. 12A and 12B coupled to an actuatable assembly interface (AAI) asdisclosed herein. AAI 800 may be similar in many aspects to the AAI 500shown in and described with reference to FIGS. 5-11. For example, AAI800 may comprise a cover 806, base 812, and locking ring 816 coupledtogether to form the housing, wherein the base may be coupled to an AAImembrane 804. AAI membrane 804 may comprise a sealing flap 858configured to form a fluid seal against an AAI receiving surface of theactuatable assembly. AAI 800 may be configured to removably couple tothe locking portion 705 of the actuatable assembly 700 via one or moreof many mechanisms described herein with reference to variousembodiments. As described with reference to FIGS. 12A and 12B, thelocking portion 705 may comprise an AAI receiving surface defining asealing surface 735 and an annular rib 730, the annular rib having avertical offset 740 with respect to the sealing surface. The annular rib730 may be disposed about the outer periphery of the sealing surface735, such that when the AAI is coupled to the actuatable assembly, theannular rib comes into contact with the bottom surface of the AAI base812 disposed about the outer periphery of the sealing flap 858, withoutcontacting the sealing flap 858. The vertical offset 740 may becalibrated to allow sufficient movement of the sealing flap to allow thesealing flap to function as an air outlet valve when the AAI islockingly coupled to the actuatable assembly. Such a configuration canallow the AAI membrane sealing flap to function as a one-way valve toexpel excess air trapped between the AAI and the actuatable assembly,thus eliminating the need for a separate one-way valve such as one-wayvalve 395 shown in and described with reference to FIG. 3B.

While FIGS. 12A-13 illustrate the actuatable assembly comprising afeature to adjust the height at which the AAI membrane sealing flap isseated against the AAI receiving surface when the AAI is locked onto theactuatable assembly, such a feature may be added to the AAI instead. Forexample, the bottom surface of the AAI base may comprise an annular ribdisposed about the outer periphery of the sealing flap, wherein theannular rib may be configured to contact the AAI receiving surface whenthe AAI is coupled to the actuatable assembly. The annular rib may havea height configured to set the sealing flap at a distance from the AAIreceiving surface predetermined to allow sufficient movement of thesealing flap for expelling trapped air between the AAI and theactuatable assembly.

FIGS. 14A-14D illustrate exemplary configurations of an actuatableassembly interface (AAI) 900 suitable for incorporation with a hydraulicpumping system as disclosed herein. AAI 900 may be configured with amechanism that enables reversible shut-off of fluid communicationbetween the breast interface and the AAI, as described herein. AAI 900may be similar in many aspects to AAI 500 shown in and described withreference to FIGS. 5-11. For example, AAI 900 may comprise a housingcoupled to an AAI membrane and a tube containing the driving fluid forthe breast shield assembly. The AAI housing may comprise a cover, alocking ring 916, and a base 912, which may be similar in many aspectsto cover 506, locking ring assembly 516, and base 512, respectively, asshown and described with reference to FIGS. 5-11.

FIG. 14A shows an exemplary configuration of a locking ring 916 of AAI900. Locking ring 916 may comprise an internal ring portion 908 and anexternal ring portion 910, which may be similar in many aspects to theinternal locking ring 508 and external locking ring 510, respectively,as described elsewhere herein. The internal and external ring portionsmay be fixedly coupled together at a predetermined orientation as shown,such that the two portions are rotationally fixed relative to oneanother. The internal ring portion 908 may comprise a partial ringhaving two ends, wherein one end may comprise a tip 928 configured topush against the tube carrying the driving fluid when AAI 900 isdetached from the actuatable assembly, as described in further detailwith reference to FIGS. 14C-14D. The internal ring portion 908 mayfurther comprise two springs 922 a and 922 b, collectively configured tohold the AAI in the locked or the unlocked configuration. The springs922 a and 922 b may be material springs integrally formed with theinternal ring portion, as shown in FIG. 14A, or they may compriseseparate components such as ball plungers or leaf fingers. The springs922 a and 922 b may be similar in many aspects to spring 522 describedwith reference to FIGS. 6A-6B. For example, each spring may comprise adetent geometry configured to engage corresponding engaging elements ofthe AAI base 912. The detent geometry may define an open detent 924 a,924 b and a shutoff detent 926 a, 926 b, wherein the open detents may beconfigured to engage the engaging elements when the AAI is locked ontothe actuatable assembly, and wherein the shutoff detents may beconfigured to engage the engaging elements when the AAI is not lockedonto the actuatable assembly. The open and shutoff detents mayconfigured such that a greater amount of force is required for anengaging element to move from the shutoff detent to the open detent thanto move from the open detent to the shutoff detent, thereby ensuringthat fluid communication between the breast interface and the AAIremains securely shut off while the AAI is not coupled to the actuatableassembly. The two springs 922 a and 922 b may be arranged symmetricallyabout the locking ring, such that the forces applied to the springs bythe corresponding engaging elements of the base 912 are distributedevenly about the locking ring. The rotational distribution of forces canimprove the structural robustness of the AAI, especially when the AAI isin the unlocked configuration and torque is exerted onto components ofthe AAI due to the tendency of the pinched tube to resume its natural(open) shape.

FIG. 14B shows an exemplary configuration of a base 912 of AAI 900. Base912 may comprise two engaging elements 942 a and 942 b, which may beintegrally formed with the base material. The engaging elements 942 aand 942 b may be configured to engage the springs 922 a and 922 b,respectively, of the locking ring 916, when AAI 900 is assembled. Base912 may further comprise a tube receiving member 930 configured tocouple to the tube carrying the driving fluid. For example, as shown inFIG. 14B, the tube receiving member may comprise a bore having an innerdiameter sized to receive the tube therein, wherein the bore is in fluidcommunication with the space between the AAI base and the AAI membranecoupled to the bottom surface of the AAI base. The tube receiving member930 may be disposed on a central portion 933 of the base bottom, whereinthe central portion 933 may be slightly raised relative to theperipheral portion 935 of the base bottom extending about the peripheryof the central portion. The AAI membrane may be coupled to the base atthe peripheral portion 935 (e.g., via an annular lip 560 as shown inFIG. 11, configured to fit within a corresponding annular groove of theperipheral portion 935) , such that a cavity or fluid reservoir isformed between the central portion 933 of the base bottom and the AAImembrane. In use, this cavity may be filled with the driving fluid forthe hydraulic pumping system (e.g., water or other substantiallyincompressible fluid), so as to fluidly couple the AAI membrane to thebreast interface membrane. Base 912 may further comprise a tube pinchingmember 929 configured to support the tube when the tube is pushed by thetip 928 of the locking ring, thereby pinching the tube shut between thepinching member 929 and tip 928. Base 912 may further comprise one ormore tube supporting members 931 configured to be disposed underneaththe tube when the tube is attached to the base. The supporting members931 may extend from the raised central portion 933 at least partiallyover the peripheral portion 935, to prevent the tube from sliding belowthe level of the locking ring tip 928 and pinching member 929 when thetube is captured between the tip 928 and pinching member 92, therebyensuring that the tube is pinched off completely when the AAI is in theshutoff configuration.

FIG. 14C is a top view of AAI 900 in the unlocked configuration, whereinthe AAI is not attached to the actuatable assembly and fluidcommunication between the AAI and the breast interface is shut off Inthe unlocked configuration, the engaging elements 942 a and 942 b of thebase 912 are held within the shutoff detents 926 a and 926 b of thesprings 922 a and 922 b, and the tip 928 of the internal ring portion908 is pushing the tube 914 into the tube pinching member 929, so as topinch the tube shut. As shown, the radial positions of the tip 928 andpinching member 929 with respect to the center of the base 912 may beslightly offset, so as to reduce the rotational forces exerted onto thesprings by the resistance of the tube to being pinched closed, andthereby more securely hold the tube pinched shut.

FIG. 14D is a top view of AAI 900 in the locked configuration, whereinthe AAI is attached to the actuatable assembly and fluid communicationbetween the AAI and the breast interface is re-opened. In the lockedconfiguration, engaging elements 942 a and 942 b of the locking ring areheld within the open detents 924 a and 924 b, and tip 928 of theinternal ring portion 908 is not pushing into the tube 914 to any extentthat substantially obstructs fluid passage through the tube.

FIGS. 15A-15C illustrate an exemplary configuration of an AAI base 1012suitable for incorporation with a hydraulic pumping system as disclosedherein. FIG. 15A shows a barbed adaptor 1013 suitable for incorporationwith an AAI as described herein. FIG. 15B shows the barbed adaptor 1013of FIG. 15A coupled to an AAI base 1012. FIG. 15C is a sidecross-sectional view of the AAI base 1012 with the barbed adaptor 1013as shown in FIG. 15B. AAI base 1012 may comprise a barbed adaptor 1013,configured to securely couple the tube carrying the driving fluid to thebase 1012. The barbed adaptor 1013 may comprise one or more barbedregions 1015 configured to couple to the tubing, and an insertion region1017 configured to insert into the bore of the tube receiving member1030 of the base. The barbed region 1015 may be shaped and dimensionedto ensure that the tube is fluidly sealed against the adaptor when thetube is disposed over the barbed region. The insertion region 1017 maycomprise one or more o-ring grooves 1019 configured to receive one ormore o-rings 1021 therein, to ensure that the adaptor is fluidly sealedagainst the bore of the tube receiving member. The barbed adaptor 1013can thereby help ensure that the joint between the tube and the AAI baseis fluidly sealed. To further secure the coupling between the adaptorand the tube receiving member, the adaptor may be glued into the bore ofthe tube receiving member. To facilitate the gluing of the adaptor tothe bore, the tube receiving member may comprise a glue potting hole1031, and the adaptor may comprise a glue potting groove 1023 configuredto align with the hole 1031 when the adaptor is inserted into the boreof the tube receiving member. Other aspects of the AAI base 1012 may besimilar to various embodiments of an AAI base as described herein.

While FIGS. 15A-15C show an AAI base comprising a separate barbedadaptor that is coupled to the base, in some embodiments, a barbedfitting for the tubing may be integrally formed with the base. Forexample, the tube receiving member may comprise a barbed fitting with abore in fluid communication with the cavity formed between the AAI baseand the AAI membrane.

While preferred embodiments of the present invention have been shown anddescribed herein, it will be obvious to those skilled in the art thatsuch embodiments are provided by way of example only. Numerousvariations, changes, and substitutions will now occur to those skilledin the art without departing from the invention. It should be understoodthat various alternatives to the embodiments of the invention describedherein may be employed in practicing the invention. It is intended thatthe following claims define the scope of the invention and that methodsand structures within the scope of these claims and their equivalents becovered thereby.

What is claimed is:
 1. An apparatus for expression of breast milk from abreast, the apparatus comprising: a breast interface configured toreceive and fluidly seal against the breast, the breast interfacecomprising a first fluid reservoir; an actuatable assembly interfaceconfigured to removably couple to an actuatable assembly, the actuatableassembly interface comprising a second fluid reservoir; and a tubehaving a first end coupled to the breast interface and a second endcoupled to the actuatable assembly interface, such that the first fluidreservoir and the second fluid reservoir are in fluid communication,wherein the first fluid reservoir, the second fluid reservoir, and thetube are filled with a driving fluid, and wherein the actuatableassembly interface comprises a fluid shutoff mechanism to reversiblyshut off fluid communication between the first fluid reservoir and thesecond fluid reservoir; wherein the fluid shutoff mechanism isconfigured to shut off fluid communication between the first and secondfluid reservoirs in response to detachment of the actuatable assemblyinterface from the actuatable assembly, and re-open the fluidcommunication in response to attachment of the actuatable assemblyinterface to the actuatable assembly; wherein the fluid shutoffmechanism is configured to simultaneously secure coupling of theactuatable assembly interface to the actuatable assembly and releasepinching of the tube to open the tube, and to simultaneously releasecoupling of the actuatable assembly interface to the actuatable assemblyand pinch the tube closed; wherein the fluid shutoff mechanism comprisesone or more springs and one or more engaging members configured toengage the one or more springs in a first configuration when theactuatable assembly interface is detached from the actuatable assembly,or in a second configuration different from the first configuration whenthe actuatable assembly interface is attached to the actuatableassembly; wherein the one or more springs comprises one or more materialsprings each having a detent geometry, the detent geometry defining afirst detent and a second detent configured to engage the one or moreengaging members in the first configuration or in the secondconfiguration, respectively.
 2. An apparatus as in claim 1, wherein thedriving fluid has a density that is higher than the density of air. 3.An apparatus as in claim 1, wherein the driving fluid is substantiallyincompressible.
 4. An apparatus as in claim 1, wherein the breastinterface comprises a first housing and a distal membrane coupledthereto to form the first fluid reservoir therebetween, wherein theactuatable assembly interface comprises a second housing and a proximalmembrane coupled thereto to form the second fluid reservoirtherebetween, and wherein the distal and proximal membranes are flexibleto allow movement of the driving fluid into or out of the first andsecond fluid reservoirs.
 5. An apparatus as in claim 4, wherein theproximal membrane is configured to seal against an actuatable assemblymembrane when the actuatable assembly interface is coupled to theactuatable assembly, wherein the actuatable assembly membrane is coupledwith a driver mechanism of the actuatable assembly, such that movementof the actuatable assembly membrane in response to actuation of thedriver mechanism causes corresponding movement of the proximal membrane.6. An apparatus as in claim 5, wherein the proximal membrane comprises asealing flap configured to allow air trapped between the proximalmembrane and the actuatable assembly membrane to exit.
 7. An apparatusas in claim 4, wherein the second housing of the actuatable assemblyinterface comprises a tube receiving member configured to couple to thesecond end of the tube, the tube receiving member defining a bore thatis in fluid communication with the second fluid reservoir through anopening in the second housing.
 8. An apparatus as in claim 5, whereinthe tube receiving member comprises a barbed region configured toreceive the tube thereover and form a fluid seal thereagainst.
 9. Anapparatus as in claim 5, wherein the actuatable assembly interfacefurther comprises a barbed adaptor configured to fit within and fluidlyseal against the bore of the tube receiving member, the barbed adaptorcomprising a barbed region configured to receive the tube thereover andform a fluid seal thereagainst.
 10. An apparatus as in claim 1, whereinthe fluid shutoff mechanism is configured to secure or release thecoupling of the actuatable assembly interface to the actuatable assemblyand simultaneously release or pinch the tube via rotational movement ofthe actuatable assembly interface with respect to the actuatableassembly.
 11. An apparatus as in claim 1, wherein the one or moresprings are configured such that a greater force is required todisengage the one or more engaging members from the one or more springsin the first configuration than in the second configuration.
 12. Anapparatus as in claim 1, wherein the fluid shutoff mechanism isconfigured to secure or release the coupling of the actuatable assemblyinterface to the actuatable assembly and simultaneously release or pinchthe tube via rotational movement of the actuatable assembly interfacewith respect to the actuatable assembly, and wherein the one or moresprings and one or more engaging members comprise a plurality ofsprings.
 13. An apparatus as in claim 12, wherein the plurality ofsprings and the plurality of engaging members are distributed in arotationally symmetric manner about the actuatable assembly interface.14. An apparatus as in claim 1, wherein the actuatable assemblyinterface comprises a keyed locking mechanism configured to allowattachment and removal of the actuatable assembly interface to and fromthe actuatable assembly only when the fluid communication between thefirst and second fluid reservoirs is shut off.
 15. A system forexpression of breast milk from a breast, the system comprising: anactuatable assembly comprising a driver mechanism coupled to anactuatable assembly membrane; and an actuatable assembly interfaceconfigured to removably couple to the actuatable assembly, theactuatable assembly interface comprising a housing and a flexiblemembrane coupled together to form a second fluid reservoir therebetween,wherein the second fluid reservoir of the actuatable assembly interfaceis in fluid communication with a first fluid reservoir of a breastinterface via a tube, and wherein the housing comprises a fluid shutoffmechanism to reversibly shut off fluid communication between the firstand second fluid reservoirs; wherein the flexible membrane is configuredto seal against the actuatable assembly membrane when the actuatableassembly interface is coupled to the actuatable assembly, such thatmovement of the actuatable assembly membrane in response to actuation ofthe driver mechanism causes corresponding movement of the flexiblemembrane; wherein the flexible membrane comprises a sealing flapconfigured to expel air trapped between the flexible membrane and theactuatable assembly membrane when the driver mechanism moves theactuatable assembly membrane towards the flexible membrane; wherein theactuatable assembly comprises a receiving surface configured to receivethe actuatable assembly interface, the receiving surface defining ansealing surface configured to seal against the sealing flap and anannular rib disposed about the outer periphery of the sealing surface,wherein the annular rib is vertically offset from the sealing surface bya height predetermined to allow sufficient movement of the sealing flapto expel the air trapped between the flexible membrane and theactuatable assembly membrane.